Methods for detecting and analyzing surface films

ABSTRACT

Disclosed herein are embodiments of a novel method and system to analyze films using plasma to produce spectral data and analyzing the spectral data.

FIELD OF INVENTION

The present disclosure is directed to a method of analyzing filmsdeposited onto a substrate by contacting the film with plasma to producespectral data and analyzing the resulting spectral data. The method isuseful in determining, e.g., the presence of a particular material on asubstrate, the composition of the film, the amount of the material inthe film, and the thickness of the film. The present disclosure isfurther directed to a system of analyzing films, wherein the film may beoptionally deposited onto a substrate or absorbed onto the substrate.

BACKGROUND

The analysis of films is a major challenge in material science. This isespecially the case when the films are deposited on a substrate. Thereexists a need in the art for a method and system of analyzing andquantifying films, such as, e.g., films that are deposited as a layer ora coating on a substrate.

OBJECTS AND SUMMARY OF THE INVENTION

It is an object of certain embodiments of the present invention toprovide a method of analyzing a film by contacting the film with plasmato produce spectral data and analyzing the spectral data.

It is an object of certain embodiments of the present invention toprovide a method of analyzing a film on a substrate by contacting thefilm with plasma to produce spectral lines and analyzing the spectrallines.

It is an object of certain embodiments of the present invention toprovide a method of extricating surface materials with plasma andrecording the spectral data of the resulting excitation of theextricated surface materials.

It is an object of certain embodiments of the present invention toprovide a method of determining the composition of a film by fragmentingcomponents of the film with a plasma comprising, e.g., argon, helium,hydrogen or oxygen, and analyzing the components.

It is an object of certain embodiments of the present invention toprovide a method of detecting and analyzing molecular fragments (e.g., afragment comprising C—N, P—O or other small organic fragments andcombinations thereof) produced by exposure to plasma.

It is an object of certain embodiments of the present invention toprovide a method of analyzing films deposited on a substrate using anoptical emissions spectrometer.

It is an object of certain embodiments of the present invention toprovide a method of analyzing the film deposited on a substrate madefrom, e.g., metal, semiconductor, glass, ceramic or other materials.

It is an object of certain embodiments of the present invention toprovide a method of determining the composition of a film deposited on,e.g., medical devices, surgical devices and implants, drainagecatheters, shunts, tapes, meshes, ropes, cables, wires, sutures, skinand tissue staples, burn sheets, external fixation devices,temporary/non-permanent implants, and other materials.

It is an object of certain embodiments of the present invention toprovide a method of measuring the thickness of a film deposited onto asubstrate or absorbed onto a substrate.

It is an objection of certain embodiments of the present invention toprovide a method of detecting the presence of an organic monolayer film.

It is an object of certain embodiments of the present invention toprovide an analysis system for implementing the methods disclosedherein. In one embodiment, the system comprises a film, a plasma, and aspectral data recording device.

It is an object of certain embodiments of the present invention toprovide a method of analyzing a film by that is simple and inexpensive.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other features of the present disclosure, their nature,and various advantages will become more apparent upon consideration ofthe following detailed description, taken in conjunction with theaccompanying drawings, in which:

FIG. 1 is an intensity versus time chromatogram illustrating therelationship between the amount of material in a film and the area underthe curve (AUC) obtained according to one embodiment of the invention.

FIG. 2 is a curve illustrating the correlation between the amount ofmaterial in a film and the AUC of FIG. 1 obtained according to oneembodiment of the invention.

FIG. 3 illustrates a substrate having a film deposited thereon accordingto an embodiment of the invention.

FIG. 4 illustrates an exemplary spectral signature generated during acleaning step according to an embodiment of the invention.

FIGS. 5A-5C illustrate exemplary spectral data used to analyze thethickness of a film according to an embodiment of the invention.

FIGS. 6A-6D illustrate exemplary spectral data used to analyze thepresence of an organic monolayer within particular detection parameteraccording to an embodiment of the invention.

FIGS. 7A-7B illustrate exemplary spectral data comparing the cleanlinessanalysis of a sample using the wet contact analysis technique and theplasma optical emission spectra technique according to an embodiment ofthe invention.

DETAILED DESCRIPTION

As used herein, the term “area under the curve” refers to the area underthe spectral line curve, or chart recorder function at a singlewavelength over time, obtained from a device producing such data.

As used herein, the term “spectral data”, refers to all the dataobtained from a device producing such data, including and not limitedto, an optical emission device. The data may include informationgenerated directly or calculated downstream, including spectral lines,AUC, peak height, peak intensity, absorbance, peak width, models orcorrelations deduced from a pattern or trend obtained from the spectraand so on.

The present invention is directed to a method of analyzing films,comprising using plasma to produce spectral data and measuring theintensity of the transient spectral lines through optical emissionspectroscopy. These emissions and resulting spectral data can berecorded over time and used to determine the amount, type, andcomposition of material present on a substrate's surface as well as thethickness of the film deposited onto the substrate. Recording andmeasuring all of the spectral lines present in the plasma assists indetecting the presence of specific elements such as nitrogen,phosphorus, chlorine, sodium and others, as well as the presence ofmolecular fragments such as any organic fragment (e.g., C—O, C—N, P—Oand combinations thereof.

In some embodiments, the invention relates to a method for analyzing afilm by contacting the film with plasma to produce spectral lines andanalyzing the spectral lines. In certain embodiments, the film may bedeposited on a substrate. This substrate may be made from a variety ofmaterials, e.g., metal, semiconductor, glass or ceramic.

In other embodiments, the invention relates to a method comprisingcontacting the film with plasma, thereby removing one or more fragmentsfrom the film which produces some of the spectral lines. In certainembodiments, the materials from the film may be excited in the plasma.In some embodiments, the plasma may comprise, e.g., argon, helium,hydrogen or oxygen.

In some embodiments, the spectral data analysis is performed with anoptical emissions spectrometer. In one embodiment, the spectrometer usesa fiber optic cable. In another embodiment, the spectrometer usesmirrors, lenses or any other tool designed to focus the light onto adetector. The spectral line, wavelength or other data produced by thefilm's exposure to plasma may be recorded over time. In one embodiment,the spectrometer measures the intensity of the spectral lines acrosstime or across varying wavelengths.

In certain embodiments, analysis of the spectral data is used todetermine the amount of material in the film. In one embodiment, theanalysis is used to determine the composition of the film. In someembodiments, the analyzed data may be carbon-based. In some embodiments,the analysis determines the thickness of the film. In certainembodiments, the analysis determines the presence of an organicmonolayer. In other embodiments, the analysis determines the presence ofvarious elements in the film, such as, e.g., nitrogen, phosphorous,chlorine, sodium and combinations thereof. In still other embodiments,the analysis may determine the presence of a molecular fragment in thefilm, such as, e.g., fragments of C—N, P—O or combinations thereof.

In some embodiments, the method of analyzing a film comprises placing afilm-coated substrate into a chamber; adding the plasma to the chamber;recording spectral data produced after addition of the plasma; andanalyzing the spectral data.

In some embodiments, the method further comprises cleaning the chamber.Cleaning the chamber may occur before or after placing the substrateinto the chamber. Cleaning may comprise filing the chamber with an inertgas where the inert gas may be argon. Another gas such as nitrogen canalso be used. In certain embodiments, cleaning may occur at a pressureranging from about 0.1 Torr to about 10 Torr, from about 0.1 Torr toabout 5 Torr or at about 0.5 Torr. In other embodiments, cleaning mayoccur at a power ranging from about 1 Watt to about 1,000 Watts, fromabout 100 Watts to about 500 Watts or at about 200 Watts. In someembodiments, cleaning may occur for a period of time ranging from about1 minute to about 60 minutes, from about 10 minutes to about 30 minutesor for about 20 minutes.

In certain embodiments, the cleaning comprises filling the chamber withargon gas at a pressure of 0.5 Torr and a power of 200 Watts for 20minutes.

In some embodiment, the method comprises cleaning the chamber containinga film, contacting the chamber with plasma, recording spectral linesduring the cleaning period, and analyzing the resultant spectral linesto identify the presence of contaminants, identity contaminants presentin the film, and the amount or quantity of the contaminants.

In some embodiments, the chamber may be degassed. Degassing the chambermay occur before or after the film-coated substrate is placed therein,and in certain embodiments the degassing occurs after the substrate isplaced in chamber. In some embodiments, degassing occurs at a pressureranging from about 0.001 Torr to about 10 Torr, from about 0.1 Torr toabout 1 Torr or at about 0.23 Torr.

After the chamber is degassed, in some embodiments the method furthercomprises flushing the chamber with an inert gas. In some of theseembodiments, the inert gas may be, but not limited to, argon ornitrogen. In some embodiments, the flushing cycles may occur at apressure ranging from about 0.001 Torr to about 10 Torr, about 0.005Torr to about 5 Torr, from about 0.1 Torr to about 1 Torr or at about0.5 Torr. In other embodiments, the flushing cycles may occur for aperiod of time ranging from about 1 minute to about 10 minutes, fromabout 1 minute to about 5 minutes or for about 3 minutes.

The degassing and flushing cycles may occur multiple times in someembodiments. In a particular embodiment, the degassing and flushingcycle occurs three times. In particular embodiments, the degassing andflushing cycles occur three times at 0.5 Torr for 3 minutes during eachcycle. In certain embodiments, the degassing and flushing removes theatmospheric carbon and moisture from the chamber.

In some embodiments, after the degassing and flushing cycle(s), plasmais added. This plasma may be, but not limited to, argon, helium,hydrogen or oxygen plasma. In some embodiments, the plasma is added to apressure ranging from about 0.1 Torr to about 10 Torr, from about 0.1Torr to about 5 Torr or at about 0.5 Torr. In other embodiments, theplasma is added at a power ranging from about 1 Watt to about 1,000Watts, from about 100 Watts to about 500 Watts or at about 200 Watts.Adding the plasma in other embodiments occurs for a period of timeranging from about 1 minute to about 60 minutes, from about 5 minutes toabout 30 minutes or for about 10 minutes.

In certain embodiments, the plasma is added at a pressure of about 0.5Torr and a power of about 200 Watts for about 10 minutes.

In some embodiments, data recorded from the method may be spectral data.This spectral data may be in the form of spectral lines. In someembodiments the spectral data is recorded with a spectrometer. Incertain embodiments, the spectral data is recorded by an opticalemission spectrometer. In certain embodiments, the spectrometer mayrecord the spectral lines in a wavelength spectrum ranging from about 1nm to 1 μm or from about 175 nm to about 950 nm. In other embodimentsthe spectral data is recorded at a rate ranging from about every 0.01seconds to about every 1 second, about every 0.05 seconds to about every0.5 seconds or about every 0.1 seconds. In still other embodiments, thespectral data is analyzed at a wavelength known to correspond to thefragments or particular elements present in the film.

In some embodiments, the thin film may be attached to the substratethrough, e.g., covalent bonds, non-covalent bonds, chemical bonds,electrostatic interactions, ionic bonds, metallic bonds, hydrogen bonds,halogen bonds, Van der Waals forces, dipole-dipole interactions,dipole-induced dipole interactions, adsorption, painting, brushing,cross-linking, chemical vapor deposition, physical vapor deposition,epitaxy, electrodeposition, thermal deposition, evaporation, sputteringor casting.

The film to be used in this invention may consist of oxide, alkoxide,mixed oxide-alkoxide, phosphonate or organophosphonate in someembodiments. In other embodiments, the film is organic or inorganic,continuous or dispersed patterned, micropatterned or smooth, a monolayeror a multilayer, naturally occurring or intentionally depositedself-assembled layer(s). In certain embodiments, the film may be aself-assembled monolayer. In other embodiments, the film may bemultilayered. In certain embodiments, as illustrated in FIG. 3, onelayer may comprise oxide, alkoxide, mixed oxide-alkoxide, phosphonate,or organophosphonate, and a second layer may comprise water andhydrocarbons. In certain embodiments the layer comprising oxide,alkoxide, mixed oxide-alkoxide, phosphonate, or organophosphonate, mayhave a thickness greater the 0.02 μm. In certain embodiments the layercomprising water and hydrocarbons has a thickness smaller than 0.005 μm.In some embodiments, the invention is directed to cleaning contaminantsfrom the layer comprising water and hydrocarbons, such that a thin filmdesired to be further analyzed remains.

In other embodiments, the method may be used where the thickness of thefilm ranged from about 0.001 μm to about 1 μm, from about 0.1 μm toabout 0.5 μm, or from about 0.1 μm to about 0.3 μm. In certainembodiments, the method may be used where the film's thickness is 1 μmor less. In some embodiments, the method may be used were the film'sthickness is 0.8 μm or less, 0.6 μm or less, 0.4 μm or less, 0.2 μm orless or 0.1 μm or less. In some particular embodiments, the method maybe used with films having a thickness ranging from about 0.0001 μm toabout 1 μm.

In other embodiments, the invention may be used to analyze films ondifferent substrates including, but not limited to a metal, alloy,polymer, plastic, ceramic, silicon, glass, tissue or fabric.

In some embodiments, the substrate may be metal, such as, e.g.,titanium, stainless steel, cobalt, chrome, nickel, molybdenum, tantalum,zirconium, magnesium, manganese, niobium, iron, gold, copper, aluminum,silver, platinum, vanadium, tin, palladium, iridium, antimony, bismuth,zinc, tungsten and alloys thereof.

In other embodiments, the substrate may be a polymer, which may beselected from the group consisting of, polyamides, polyurethanes,polyureas, polyesters, polyketones, polyimides, polysulfides,polysulfoxides, polysulfones, polythiophenes, polypyridines,polypyrroles, polyethers, silicones, polysiloxanes, polysaccharides,fluoropolymers, amides, imides, polypeptides, polyethylene, polystyrene,polypropylene, glass reinforced epoxies, liquid crystal polymers,thermoplastics, bismaleimide-triazine (BT) resins, benzocyclobutenepolymers, Ajinomoto Buildup Films (ABF), low coefficient of thermalexpansion (CTE), films of glass and epoxies, polyethylene terephthalate(PET), polyetheretherketones (PEEK), and polyetherketoneketones (PEKK)or combinations thereof. In certain embodiments, the polymer may beselected from the group consisting of polyethylene terephthalates (PET),polyetheretherketones (PEEK), or polyetherketoneketones (PEKK) andcombinations thereof.

In other embodiments, the substrate may be a plastic. In someembodiments, the plastic may be selected from the group consisting ofpolyolefins, polyethylene/acrylate copolymers, polyacrylate homo andcopolymers, phenoxy polymers, polystyrenes and copolymers, polyacetal(polyoxymethylene) homo and copolymers, polycarbonates, polyethylenes,naphthalates, polyamide/imides, polybenzimidazoles, synthetic rubbers,vinyl polymers, cellulose derivatives, polybutylenes, ethylene methylacrylates, polyethylene terephthalates, polybutylene terephthalates,nylon 6, nylon 6,6, nylon 4,6, nylon 11, nylon 12, aramids,polymethylmethacrylates, sulfone,s epichlorohydrin/bisphenol resins,polyacrylonitrile/butadiene/styrenes (ABS), polyamide/imides,ethylene-chlorotrifluoroethylenes, ethylene/propylene/diene monomers(EPDM), chlorinated rubbers, nitro rubbers, styrene butadiene rubbers,polylactides, polyvinyl acetates and copolymers, polyvinyl butyrals,polyvinyl chlorides, cellulose acetate homopolymers and copolymers withcellulose propionate and cellulose butyrates, nitro celluloses andcombinations thereof.

In other embodiments, the substrate may be a ceramic. In someembodiments, the ceramic may be calcium phosphates, calcium phosphatecements, biocompatible magnesium doped calcium phosphates, calciumcarbonates, calcium sulfates, barium carbonates, barium sulfates,alphatricalcium phosphates (a-TCP), tricalcium phosphates (TCP),betatricalcium phosphates (β-TCP), hydroxyapatites (HA), biphasiccalcium phosphates, biphasic composite between HA and β-TCP, aluminas,zirconias, bioglasses, biocompatible silicate glasses, biocompatiblephosphate glasses and combinations thereof.

In other embodiments, the substrate may be a silicon, including but notlimited to, amorphous silicons, undoped polysilicons, dopedpolysilicons, single crystal silicons, monocrystalline silicons,polycrystalline silicons, nanocrystalline silicons, porous silicons,polycrystalline silicons and combinations thereof.

In other embodiments, the substrate may be a glass, including but notlimited to, silicate glasses, perlite glasses, zonalites glasses,fermiculite glasses, soda lime silicas, borosilicate glasses,aluminosilicate glasses, borate glasses, phosphate glasses, oxideglasses, halide glasses, sulfide glasses, chalcogenide glasses,pre-fused glasses, recycled glasses, manufactured glasses andcombinations thereof.

In other embodiments, the substrate may be a tissue, including but notlimited to, connective tissues, non-connective tissues, tendons tissues,ligament tissues, blood vessel tissues, arterial tissues, venoustissues, neural tissues, organ tissues, fascias, pericardial tissues,dermal tissues, adipose tissues, dura tissues, fibrous tissues,cartilage tissues, bone tissues, placental tissues, endothelial tissues,epithelial tissues, epidermal tissues, synovial membranes, muscletissues, mucus membrane tissues and cardiac tissues.

In other embodiments, the substrate may be a fabric, including but notlimited to, polyesters, nylons, acetates, acrylics, polycottons,cottons, cotton-polyester blends, silks, knits, wools, aramids,canvases, meshes, rayons, nonwovens, spun bonded, gauzes, cashmeres, wetlaid nonwoven fabrics of polyolefins, nylons, rayons, cellulosic fibersand combinations thereof.

In some embodiments, the substrate may be a medical device, includingbut not limited to, an implantable or percutaneous medical device,endoscopic, arthroscopic, laproscopic, cardiac, cardiovascular, vascularmedical device, orthopedic, orthopedic trauma, spine medical device,surgical devices, implants, drainage catheters, shunts, tapes, meshes,ropes, cables, wires, sutures, skin and tissue staples, burn sheets,external fixation devices or temporary/non-permanent implants.

In some embodiments, this invention is directed to a system foranalyzing films comprising a film; a plasma; and a spectral datarecording device. In other embodiments, the system for analyzing a filmmay comprise a substrate with a film; a chamber; plasma; and a spectralline recording device.

In certain embodiments, algorithms for the data analysis and deviceoperation described herein may be executed by a computer system asdescribed below. The computer system may operate in the capacity of aserver or a client machine in client-server network environment, as apeer machine in a peer-to-peer (or distributed) network environment, oras a component of a laboratory or industrial-scale machine (e.g., aplasma chamber, spectrometer or characterization device). The computersystem may be a personal computer (PC), a tablet PC, a set-top box(STB), a Personal Digital Assistant (PDA), a cellular telephone, a webappliance, a server, a network router, switch or bridge, or any machinecapable of executing a set of instructions (sequential or otherwise)that specify actions to be taken by that computer system.

An exemplary computer system includes one or more of a processing device(processor), a main memory (e.g., read-only memory (ROM), flash memory,dynamic random access memory (DRAM) such as synchronous DRAM (SDRAM) orRambus DRAM (RDRAM), etc.), a static memory (e.g., flash memory, staticrandom access memory (SRAM), etc.), or a data storage device, each ofwhich may communicate with each other via a bus.

The processor may correspond to a general-purpose processing device suchas a microprocessor, central processing unit, or the like. Moreparticularly, the processor may be a complex instruction set computing(CISC) microprocessor, reduced instruction set computing (RISC)microprocessor, very long instruction word (VLIW) microprocessor, or aprocessor implementing other instruction sets or processors implementinga combination of instruction sets. The processor may also be one or morespecial-purpose processing devices such as an application specificintegrated circuit (ASIC), a field programmable gate array (FPGA), adigital signal processor (DSP), network processor, or the like. Theprocessor may be configured to execute instructions for performing anyalgorithms useful for carrying out embodiments described herein.

The computer system may further include a network interface device. Thecomputer system also may include a video display unit (e.g., a liquidcrystal display (LCD), a cathode ray tube (CRT), or a touch screen), analphanumeric input device (e.g., a keyboard), a cursor control device(e.g., a mouse), and a signal generation device (e.g., a speaker).

The data storage device may include a computer-readable storage mediumon which is stored one or more sets of instructions (e.g., software)embodying any one or more of the methodologies or functions describedherein. The instructions may also reside, completely or at leastpartially, within the main memory and/or within the processor duringexecution thereof by the computer system, the main memory and theprocessor also constituting computer-readable storage media. Theinstructions may further be transmitted or received over a network viathe network interface device.

It is noted that the term “computer-readable storage medium” should betaken to include a single medium or multiple media (e.g., a centralizedor distributed database, and/or associated caches and servers) thatstore the one or more sets of instructions. The term “computer-readablestorage medium” shall also be taken to include any transitory ornon-transitory medium that is capable of storing, encoding or carrying aset of instructions for execution by the machine and that cause themachine to perform any one or more of the methodologies of the presentdisclosure. The term “computer-readable storage medium” shallaccordingly be taken to include, but not be limited to, solid-statememories, optical media, and magnetic media.

A power device may monitor a power level of a battery used to power thecomputer system or one or more of its components. The power device mayprovide one or more interfaces to provide an indication of a powerlevel, a time window remaining prior to shutdown of computer system orone or more of its components, a power consumption rate, an indicator ofwhether computer system is utilizing an external power source or batterypower, and other power related information. In some embodiments,indications related to the power device may be accessible remotely(e.g., accessible to a remote back-up management module via a networkconnection). In some embodiments, a battery utilized by the power devicemay be an uninterruptable power supply (UPS) local to or remote fromcomputer system. In such embodiments, the power device may provideinformation about a power level of the UPS.

Some portions of the detailed description may be performed throughexecution of algorithms. Algorithmic descriptions and representationsare the means used by those skilled in the data processing arts to mosteffectively convey the substance of their work to others skilled in theart. An algorithm is herein, and generally, conceived to be aself-consistent sequence of steps leading to a desired result. The stepsare those requiring physical manipulations of physical quantities.Usually, though not necessarily, these quantities take the form ofelectrical or magnetic signals capable of being stored, transferred,combined, compared, and otherwise manipulated. It has proven convenientat times, principally for reasons of common usage, to refer to thesesignals as bits, values, elements, symbols, characters, terms, numbers,or the like.

It should be borne in mind, however, that all of these and similar termsare to be associated with the appropriate physical quantities and aremerely convenient labels applied to these quantities. Unlessspecifically stated otherwise as apparent from the preceding discussion,it is appreciated that throughout the description, discussions utilizingterms such as “generating”, “quantifying”, “analyzing” and“determining”, or the like, refer to the actions and processes of acomputer system, or similar electronic computing device, thatmanipulates and transforms data represented as physical (e.g.,electronic) quantities within the computer system's registers andmemories into other data similarly represented as physical quantitieswithin the computer system memories or registers or other suchinformation storage, transmission or display devices.

The disclosure also relates to an apparatus, device, or system forperforming the operations herein. This apparatus, device, or system maybe specially constructed for the required purposes, or it may include ageneral purpose computer selectively activated or reconfigured by acomputer program stored in the computer. Such a computer program may bestored in a computer- or machine-readable storage medium, such as, butnot limited to, any type of disk including floppy disks, optical disks,compact disk read-only memories (CD-ROMs), and magnetic-optical disks,read-only memories (ROMs), random access memories (RAMs), EPROMs,EEPROMs, magnetic or optical cards, or any type of media suitable forstoring electronic instructions.

The following is an example of a detailed analysis performed on a thinfilm deposited on titanium alloy substrate samples. It is set forth toassist in understanding the invention and should not, of course, beconstrued as specifically limiting the invention described and claimedherein. Such variations of the invention, including the substitution ofall equivalents now known or later developed, which would be within thepurview of those skilled in the art, and changes in formulation or minorchanges in experimental design, are to be considered to fall within thescope of the invention incorporated herein.

EXAMPLE 1

Samples of titanium alloy were thoroughly cleaned using a series ofdetergent washes followed by sonication in water and ethanol. Controlsamples were set aside in clean glass containers for subsequentanalysis. A stock solution of MDPB (methacryloyloxydodecylpyridiniumbromide) was prepared in deionized water at a concentration of 1 mg/ml.A 10× dilution series was performed from the stock solution and 100 μlof the stock and each of two dilutions was pipetted onto clean titaniumalloy samples so that the following amounts of MDPB were present on theseries of samples: 0.1 mg, 0.01 mg and 0.001 mg.

In addition, a sample was prepared with 100 μl of water so that it couldbe used as a control.

All of the titanium alloy samples were then placed in an oven set at atemperature of 120° C. to evaporate the water leaving a thin film ofMDPB on the surface. The coupons were aged in the oven for 30 minutes toallow for exhaustive removal of moisture from the surface.

An Autoglow (Glow Research) plasma chamber with an integrated fiberoptic cable connected to a QE Pro Spectrometer (Ocean Optics) was usedfor cleaning and spectral analysis. Prior to testing the titanium alloysamples, the quartz chamber of the Autoglow was cleaned using argon gasat a pressure of 0.5 Torr and a power of 200 Watts for 20 minutes. Afterthe chamber was cleaned, the samples were each tested using thefollowing procedure.

A single coupon was placed in the center of the chamber and the chamberwas vacuum degassed to a pressure of 0.23 Torr. Next the chamber wasflushed with argon gas for three minutes at a pressure of 0.5 Torr. Thisvacuum/purge cycle was repeated two additional times in order toexhaustively remove atmospheric carbon contamination and any remainingmoisture.

Following the vacuum/purge cycles, an argon plasma at 0.5 Torr and 200Watts was struck for 10 minutes. Immediately upon establishing theplasma, the spectrometer was set to record the entire spectrum from 175nm to 950 nm every 0.1 seconds for the duration of the plasma treatment.

The flushing and degassing cycle was repeated for each sample, followedby a plasma treatment and similar optical emission spectrometryanalysis. Between each sample analysis the chamber was cooled down for10 minutes under vacuum.

The spectral data was analyzed. Spectral data in several wavelengthsshowed a relationship or correlation between peak height and thestarting MDPB concentration. From all wavelengths showing a correlationbetween peak height and the starting MDPB concentration, a wavelength of386 nm was selected for detailed analysis. A wavelength of 386 nm isknown to correspond to C—N fragments, thereby assisting in detecting thetype of material (e.g., elements or fragments) in the film.

Once a wavelength for detailed analysis was selected, a chart recorderanalysis was implemented to track the peak height at 386 nm as afunction of time. The resulting chromatogram is shown in FIG. 1 below.It is apparent that there is a dose dependent relationship between MDPBconcentration and area under these curves. A sample with a higherstarting concentration results in a higher material dose or amountdeposited on the substrate, thereby resulting in a higher peak, a widerpeak, and a greater area under the curve as compared to samples withlower starting concentration.

To further explore the relationship between MDPB starting concentrationor MDPB amount in the film and the area under the curve, the area wascalculated by performing an integration of the curves. A plot of thestarting concentration as a function of the area under the curve wasplotted as illustrated in FIG. 2. A curve fit was performed on thestaring concentration versus AUC data points resulting in a correlationcoefficient of R²=0.9982 indicating that the technique can be used toaccurately determine mass on a substrate. The curve fit and correlationcoefficient are illustrated in FIG. 2.

EXAMPLE 2

Coupons of plain titanium alloy foil during cleaning were cleaned withargon plasma at a power of 100 W. The optical emission spectra wasrecorded. The optical emission spectra obtained after five second ofplasma exposure time is illustrated in FIG. 4. The emission peaks wereanalyzed and possible identifications of the various contaminants wereobtained based on correlations between the various elements or molecularfragments and their absorbance at varying wavelengths.

FIG. 4 illustrates the ability of the present invention to produceoptical emission spectrum showing the presence of specific contaminantsand allowing identification of the various contaminants.

EXAMPLE 3

Three coupons of titanium alloy foil were tested: plain titanium alloyfoil, PUL coated titanium, and titanium alloy foil with an adsorbedpolymer TPL. Optical emission spectra was generated over a period of onehour of cleaning in argon plasma at a power of 100 W.

FIG. 5A shows the spectral data for bare titanium and illustrates that aplain titanium alloy foil has surface contaminants that are rapidlyremoved from the surface since after about 6 to about 30 seconds (0.1 toabout 0.5 of a minute), the resultant optical emission spectral data wassubstantially unchanged.

FIG. 5B shows the spectral data for PUL coated titanium and illustratesthat it is also cleaned from the surface contaminants rapidly sinceafter about 6 to about 30 seconds (0.1 to about 0.5 of a minute), theresultant optical emission spectral data was substantially unchanged.Without being bound to theory, it is believed that the contaminants areeasily cleaned from the sample because PUL was deposited on the surfaceas a very thin film, arguably as a monolayer about 2 nm to about 5 nmthick.

FIG. 5C shows the spectral data for a titanium alloy foil with adsorbedpolymer TPL. The adsorbed polymer layer was expected to be much thicker.Indeed, FIG. 5C illustrates that it took significantly longer to removeall of the material, as the optical emmisions spectral data keptchanging even after 30 seconds to 90 seconds (0.5 to about 1.5 of aminute).

FIGS. 5A through 5C illustrate that there is a correlation the resultantspectral data and the thickness of the film analyzed. The thicker thefilm, the longer it takes to remove all of the material from it (whereremoval of all of the material from the film is identified by a steadyunchanged spectral data across at least two time points).

EXAMPLE 4

Three samples were tested including: bare titanium, titanium coated withPUL, and titanium with adsorbed with organics such as MDPB. Since MDPBcontains Nitrogen, the system was able to detect the presence of CNfragments at 386 nm (as described in example 1) as well as the presentof carbon at 419 nm. All three samples were analyzed at two wavelengths,namely: 386 nm and 419 nm, and at two power levels, namely: 25 W and 100W.

FIGS. 6A (386 nm, 25 W) illustrates that similar amounts of CN fragmentswere present on the bare titanium and the titanium coated with PUL(presumed to have a thin layer of film ranging in thickness from about 2nm to about 5 nm). FIGS. 6A further illustrate that in the sample oftitanium adsorbed with organics such as MDPB, the level of CN fragmentswas elevated when compared to the other two samples. This informationhas the ability to give atomic identity of the consituents of the film.

FIG. 6B (419 nm, 25 W) illustrates that there is an increase in totalcarbon (area under the curve) for the titanium sample adsorbed withorganics, particularly when compared to the total carbon detected forbare titanium or for titanium coated with PUL. This shows that analyzinga film according to an embodiment of the invention has the sensititivityto detect a film comprising an organic monolayer on a surface.

FIGS. 6C (386 nm, 100 W) and 6D (419 nm, 100 W) illustrate somewhatsimilar patterns to those observed in FIGS. 6A and 6B, although some ofthe information is lost. Accordingly, in some embodiments, the method ofthe present invention may be directed to any acceptable RF power level,e.g., up to about 100 W, or an RF ranging between 5 W and 2000 W withvariations in the chamber size, vacuum pressure and gas flow rate.

EXAMPLE 5

Surface cleanliness of bare titanium cleaned in plasma was studied usingthe wet contact analysis (WCA) technique and subsequently the opticalemission spectra technique according to an embodiment of the invention.

As illustrated in FIG. 7A, after about one minute of cleaning with argonplasma, the analyzed samples achieved a contact angle of about 0, andappeared clean by the WCA technique. However, FIG. 7B illustrates thataccording to plasma optical emission spectra data, the surface thatappeared clean by the WCA technique, still had residual contaminants.Thus, in some embodiments of the present invention, the method ofanalyzing a film can provide real time cleanliness information withgreater sensitivity than other techniques known in the art.

One of ordinary skill in the art would recognize that this method may beused, for example, to determine the type of material present in a film(e.g., based on optimal absorbance at a certain wavelength), and theamount and/or composition of the material present in the film (e.g.,based on a predetermined correlation between the area under the curve asample mass or concentration).

For simplicity of explanation, the embodiments of the methods of thisdisclosure are depicted and described as a series of acts. However, actsin accordance with this disclosure can occur in various orders and/orconcurrently, and with other acts not presented and described herein.Furthermore, not all illustrated acts may be required to implement themethods in accordance with the disclosed subject matter. In addition,those skilled in the art will understand and appreciate that the methodscould alternatively be represented as a series of interrelated statesvia a state diagram or events.

In the foregoing description, numerous specific details are set forth,such as specific materials, dimensions, processes parameters, etc., toprovide a thorough understanding of the present invention. Theparticular features, structures, materials, or characteristics may becombined in any suitable manner in one or more embodiments. The words“example” or “exemplary” are used herein to mean serving as an example,instance, or illustration. Any aspect or design described herein as“example” or “exemplary” is not necessarily to be construed as preferredor advantageous over other aspects or designs. Rather, use of the words“example” or “exemplary” is intended to present concepts in a concretefashion. As used in this application, the term “or” is intended to meanan inclusive “or” rather than an exclusive “or”. That is, unlessspecified otherwise, or clear from context, “X includes A or B” isintended to mean any of the natural inclusive permutations. That is, ifX includes A; X includes B; or X includes both A and B, then “X includesA or B” is satisfied under any of the foregoing instances. In addition,the articles “a” and “an” as used in this application and the appendedclaims should generally be construed to mean “one or more” unlessspecified otherwise or clear from context to be directed to a singularform. Reference throughout this specification to “an embodiment”,“certain embodiments”, or “one embodiment” means that a particularfeature, structure, or characteristic described in connection with theembodiment is included in at least one embodiment. Thus, the appearancesof the phrase “an embodiment”, “certain embodiments”, or “oneembodiment” in various places throughout this specification are notnecessarily all referring to the same embodiment.

The term “about”, when referring to a physical quantity, is to beunderstood to include measurement errors within, and inclusive of 2%.For example, “about 100° C.” should be understood to mean “100±1° C.”

The present invention has been described with reference to specificexemplary embodiments thereof. The specification and drawings are,accordingly, to be regarded in an illustrative rather than a restrictivesense. Various modifications of the invention in addition to those shownand described herein will become apparent to those skilled in the artand are intended to fall within the scope of the appended claims.

What is claimed is:
 1. A system for analyzing a film comprising a film;a plasma; and a spectral data recording device.
 2. The system accordingto claim 1, wherein the film is deposited on a substrate.
 3. The systemaccording to claim 2, wherein the substrate comprises a metal,semiconductor, glass or ceramic.
 4. The system according to claim 1,comprising an optical emissions spectrometer.
 5. The system according toclaim 1, wherein the system is capable of determining the composition ofthe film.
 6. The system according to claim 5, wherein the system iscapable of determining the presence of an element.
 7. The systemaccording to claim 6, wherein the element is selected from the groupconsisting of carbon, oxygen, fluorine, phosphorous, chlorine, sodium,sulfur, silicon, boron and combinations thereof.
 8. The system accordingto claim 5, wherein the system is capable of determining the presence ofa molecular fragment.
 9. The system according to claim 8, wherein themolecular fragment is selected from the group consisting of C—O, C—N,P—O and combinations thereof.
 10. The system according to claim 1,wherein the system is capable of analyzing spectral lines across varyingwavelengths and/or analyzing an intensity of the spectral lines at aselected wavelength.
 11. The system according to claim 1, wherein theplasma comprises argon plasma, helium plasma, hydrogen plasma or oxygenplasma.
 12. The system according to claim 2, wherein the film isattached to the substrate through covalent bonds or through non-covalentbonds.
 13. The system according to claim 1, wherein the film is selectedfrom the group consisting of oxide, alkoxide, mixed oxide-alkoxide,phosphonate or organophosphonate.
 14. The system according to claim 1,wherein the film is organic.
 15. The system according to claim 1,wherein the film is inorganic.
 16. The system according to claim 1,wherein the film is continuous.
 17. The system according to claim 1,wherein the film is dispersed.
 18. The system according to claim 1,wherein the film is a mono- or multilayer film.
 19. The system accordingto claim 1, wherein the film has a thickness ranging from about 0.001 μmto about 1 μm.
 20. The system according to claim 1, wherein the film hasa thickness of about 0.5 μm or less.
 21. The system according to claim1, wherein the film comprises a pattern or micropattern.
 22. The systemaccording to claim 2, wherein the substrate is selected from the groupconsisting of a metal, alloy, polymer, plastic, ceramic, silicon, glass,tissue and fabric.
 23. The system according to claim 2, wherein thesubstrate is a metal selected from the group consisting of titanium,stainless steel, cobalt, chrome, nickel, molybdenum, tantalum,zirconium, magnesium, manganese, niobium, iron, gold, copper, aluminum,silver, platinum, vanadium, tin, palladium, iridium, antimony, bismuth,zinc, tungsten and alloys thereof.
 24. The system according to claim 2,wherein the substrate is a polymer or plastic.
 25. The system accordingto claim 1, wherein the substrate is a medical device.